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  <title>延缓执行</title>
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    <li><a href="index.html">PHP Manual</a></li>
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  <div id="layout-content"><div id="function.sleep" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">sleep</h1>
  <p class="verinfo">(PHP 4, PHP 5, PHP 7, PHP 8)</p><p class="refpurpose"><span class="refname">sleep</span> &mdash; <span class="dc-title">延缓执行</span></p>

 </div>
 
 <div class="refsect1 description" id="refsect1-function.sleep-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>sleep</strong></span>(<span class="methodparam"><span class="type">int</span> <code class="parameter">$seconds</code></span>): <span class="type">int</span></div>

  <p class="simpara">
   程序延迟执行指定的 <code class="parameter">seconds</code> 的秒数。
  </p>
  <blockquote class="note"><p><strong class="note">注意</strong>: 
   <p class="para">
    为了让程序执行延迟几分之一秒，应使用 <span class="function"><a href="function.usleep.html" class="function">usleep()</a></span>，因为 <span class="function"><strong>sleep()</strong></span>
    需要 <span class="type">int</span>。例如 <code class="code">sleep(0.25)</code> 会使程序暂停 <code class="literal">0</code> 秒。
   </p>
  </p></blockquote>
 </div>


 <div class="refsect1 parameters" id="refsect1-function.sleep-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>
    
     <dt>
<code class="parameter">seconds</code></dt>

     <dd>

      <p class="para">
       暂停的秒数（必须大于或等于 <code class="literal">0</code>）。
      </p>
     </dd>

    
   </dl>

  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.sleep-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   成功时返回 0。
  </p>
  <p class="para">
   如果函数的调用被一个信号中止，<span class="function"><strong>sleep()</strong></span> 会返回一个非零的值。在
   Windows 上，该值总是 <code class="literal">192</code>（即 Windows API 常量
   <strong><code>WAIT_IO_COMPLETION</code></strong> 的值）。其他平台上，该返回值是剩余未 sleep 的秒数。
  </p>
 </div>


 <div class="refsect1 errors" id="refsect1-function.sleep-errors">
  <h3 class="title">错误／异常</h3>
  <p class="para">
   如果指定的 <code class="parameter">seconds</code> 是负数，该函数会抛出 <span class="classname"><a href="class.valueerror.html" class="classname">ValueError</a></span>。
  </p>
 </div>


 <div class="refsect1 changelog" id="refsect1-function.sleep-changelog">
  <h3 class="title">更新日志</h3>
  <table class="doctable informaltable">
   
    <thead>
     <tr>
      <th>版本</th>
      <th>说明</th>
     </tr>

    </thead>

    <tbody class="tbody">
     <tr>
      <td>8.0.0</td>
      <td>
       此函数在负数 <code class="parameter">seconds</code> 时抛出 <span class="classname"><a href="class.valueerror.html" class="classname">ValueError</a></span>，之前会引发
       <strong><code>E_WARNING</code></strong> 且函数返回 <strong><code>false</code></strong>。
      </td>
     </tr>

    </tbody>
   
  </table>

 </div>


 <div class="refsect1 examples" id="refsect1-function.sleep-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-3462">
    <p><strong>示例 #1 <span class="function"><strong>sleep()</strong></span> 示例</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /><br /></span><span style="color: #FF8000">//&nbsp;当前时间<br /></span><span style="color: #007700">echo&nbsp;</span><span style="color: #0000BB">date</span><span style="color: #007700">(</span><span style="color: #DD0000">'h:i:s'</span><span style="color: #007700">)&nbsp;.&nbsp;</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">//&nbsp;睡眠&nbsp;10&nbsp;秒<br /></span><span style="color: #0000BB">sleep</span><span style="color: #007700">(</span><span style="color: #0000BB">10</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">//&nbsp;醒来！<br /></span><span style="color: #007700">echo&nbsp;</span><span style="color: #0000BB">date</span><span style="color: #007700">(</span><span style="color: #DD0000">'h:i:s'</span><span style="color: #007700">)&nbsp;.&nbsp;</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br /><br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
    </div>

    <div class="example-contents"><p>
     该例子会在休眠10秒后输出。
    </p></div>
    <div class="example-contents screen">
<div class="cdata"><pre>
05:31:23
05:31:33
</pre></div>
    </div>
   </div>
  </p>
 </div>


 <div class="refsect1 seealso" id="refsect1-function.sleep-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="function.usleep.html" class="function" rel="rdfs-seeAlso">usleep()</a> - 以指定的微秒数延迟执行</span></li>
    <li class="member"><span class="function"><a href="function.time-nanosleep.html" class="function" rel="rdfs-seeAlso">time_nanosleep()</a> - 延缓执行若干秒和纳秒</span></li>
    <li class="member"><span class="function"><a href="function.time-sleep-until.html" class="function" rel="rdfs-seeAlso">time_sleep_until()</a> - 使脚本睡眠到指定的时间为止</span></li>
    <li class="member"><span class="function"><a href="function.set-time-limit.html" class="function" rel="rdfs-seeAlso">set_time_limit()</a> - 设置脚本最大执行时间</span></li>
   </ul>
  </p>
 </div>


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